1. Field of the Invention
The field of the present invention relates generally to hot water heaters and more particularly to instantaneous demand hot water heaters.
2. Background Art
The present inventor is familiar with the following three U.S. patents which are hereby fully incorporated herein for all purposes by this specific reference:
______________________________________ U.S. Pat. No. Inventor ______________________________________ 1,901,761 Wilmer E. McCorquodale 2,974,650 Alan B. McCorquodale 3,320,935 Alan B. McCorquodale ______________________________________
By instantaneous demand is meant a hot water heater that provides an output of heated water in response to user demand. The water is heated while flowing through coils or tubes rather than heating a tank or reservoir filled with water as in conventional household water heaters. The latter arrangement is relatively inefficient in use of energy in requiring the heating and maintaining a large volume of water in heated readiness. In addition, the tank type heater is not suitable for long periods of continuous high consumption use and is not responsive to intermittent demand. The capability to respond rapidly to the heated water use or demand results in the instantaneous demand nomenclature.
U.S. Pat. No. 1,901,761 is entitled "Hot Water Heater Attachment" and discloses four embodiments of an instantaneous demand responsive gas fired hot water heater. All four embodiments disclosed utilize an external recirculation flow casing for circulating the heated water with the water temperature sensing thermostat positioned in the external casing for controlling gas flow to the burner. In all four embodiments the cold water is injected into the external casing for circulation past the water temperature sensing thermostat prior to passage into the heating coil. When flow of water is discontinued through coils and due to the thermostat location, the burner continues operation until sufficient heated water is recirculated down the recirculation casing to displace the cold water and contact the thermostat.
U.S. Pat. No. 2,974,650 is entitled "Water Heater With Side Wall Venting Means." The disclosed gas fired water heater is particularly suited for use in automobile trailers as the flue gas is safely discharged through the heater side wall. The gas burner heats an ovate reservoir tank having the thermostat located adjacent the bottom of the tank. The disclosed conventional reservoir heater is not of the instantaneous demand type, but is rather of the conventional type in sensing the water temperature in the tank.
U.S. Pat. No. 3,320,935 is an improvement of U.S. Pat. No. 2,974,650 and is entitled "Water Heater With Side Wall Air Supply and Venting Means." The disclosed hot water heater insures that all flow of air is directly to the burner and then as flue gas outwardly through the side wall vent.
3. Objects of the Present Invention
An object of the present invention is to provide a new and improved hot water heater.
A further object is to provide a new and improved instantaneous demand gas fired hot water heater.
Yet another object is to provide a new and improved instantaneous demand hot water heater that is sensitive in response to demand usage and economical in operation.